Reagan's opening gambit on way to serious nuclear arms control talks with Soviet Union

With one bold stroke, President Reagan appears to have taken the psychological, political and propaganda inititave away from the Soviets in the arms confield.

In presenting the Soviet Union with a proposal for deep mutual cuts in nuclear arms, the Reagan administration is attempting to offset the growing antinuclear and neutralist sentiment which has worked to the President's disadvantage in Western Europe.

The proposal also serves as a benchmark in the education of an American president. Faced with mounting economic difficulties at home and the danger of a growing schism with the NATO allies, the President now appears to be rethinking his earlier opposition to arms control agreements with the Soviets. And, at a minimum, the Soviets must now attempt to counter the Reagan proposal. Otherwise , they might be successfully tagged with the title of the real threat to Western Europe.

Accordingly, the Soviets began to denounce the Reagan proposal almost as soon as the President made it public in a televised speech Nov. 18 before the National Press Club in Washington.

Tass, the official Soviet news agency, published an article declaring that the American proposal for the elimination of medium-range missiles in Europe ''cannot lead to any positive results.'' That American proposal, which was the single most important part of the Reagan speech, calls for the Soviets to dismantle their SS-20, SS-4, and SS-5 missiles. According to Reagan, these missiles carry 1,100 warheads capable of striking targets in Western Europe. The US, the President said, has no comparable missiles.

In return for such Soviet dismantling, the US would agree not to deploy the 572 new ground-launched cruise and Pershing II missiles which it now plans to place in Western Europe over the next few years.

In other words, the US is asking the Soviets to scrap all their existing medium-range missiles aimed at Western Europe in return for an American decision to hold off deploying in Europe a smaller number of missiles, none of which is yet in place. There is, furthermore, no guarantee as of yet that the West Europeans will allow those American missiles to be deployed. Thus, the initial negative Soviet reaction was predictable. It remains to be seen, however, whether the Reagan proposal can serve as the basis for bargaining. It is, after all, an opening position. And Tass is far from being Moscow's final word.

Reagan administration officials, meanwhile, seem to be watching West European reactions at the moment even more carefully than they are those from Moscow. From West European governments, those reactions have so far been largely positive. In the words of one West German analyst, the US and its allies now have gained ''some real breathing space'' in the face of a major Soviet peace offensive aimed at winning over West European public opinion.

Most Reagan administration officials started out extremely skeptical of almost any kind of agreement with the Soviets. But many of them reluctantly have come to the conclusion that unless they showed the West Europeans that the US was serious in its pursuit of arms control, US relations with West Europe would be severely damaged - and perhaps damaged to the point where new US missiles could not be deployed to offset what the administration perceives to be Soviet superiority in Europe.

In his National Press Club speech, President Reagan left so many questions unanswered about the US negotiating position that specialists outside the government remained unsure what the American fallback position would be should the Soviets definitively reject the Reagan initiative. Some officials seem to want to make that initiative a take-it-or-leave-it offer, while others are apparently arguing for more flexibility. One criticism which some Reagan administration officials had of the Carter administration was that it backed away too quickly from arms control proposals which it made to the Soviets.

In an appearance on the WETA television program ''American Interests'' on the eve of the Reagan speech, Assistant Secretary of Defense Richard Perle said that ''the difference with Carter is that the Carter administration backed off within a matter of weeks. President Reagan is going to stay there until he gets an acceptance.''

Beyond the details, however, what is clear is that President Reagan has markedly changed the tone of his public stance on arms control. He has stopped, for the moment at least, linking arms control progress with other aspects of Soviet behavior. He has shown a willingness to listen to West European concerns - and not to label them as he did in the past as simply a result of Soviet propaganda efforts. He also has accommodated to those concerns by showing a willingness to consider not deploying new US missiles in Europe within the context of arms control agreements. His speech will make it more difficult for his opponents in Europe to label him a warmonger.

In his speech, which was his first major foreign policy address as President, Reagan called for talks with the Soviets on reducing long-range nuclear weapons as soon as possible next year. Talks on cutting back medium-range missiles based in Europe are to begin in Geneva on Nov. 30. Given the wide differences apparently still existing between the US and Soviet sides even over the question of which weapons should be included in such talks, few experts expect the Geneva talks to be anything but prolonged.

The President also proposed that the two sides work toward achieving ''equality at lower levels'' in their conventional or nonnuclear military forces based in Europe. Finally, in a message to President Brezhnev, Reagan renewed a Western proposal for a conference to reduce the risks of a surprise nuclear attack arising out of uncertainty or miscalculation.

Speaking of his proposal for a reduction in medium-range nuclear missiles, President Reagan said that ''This, like the first footstep on the moon, would be a giant step for mankind.''